Invalidity dossier
US 6939027
Added 9/23/2026, 6:29:47 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 6,939,027 B2
Title: Light source system (US6939027B2)
Assignee: Topcon Corp (original assignee; assignment to Kabushiki Kaisha Topcon recorded 2003-11-12)
Inventor: Yuko Harumoto
Priority date: 2002-07-09; Filed: 2003-07-08; Published (application): 2004-04-08 as US20040066651A1; Granted: 2005-09-06.
Status per source: Expired – Fee Related; anticipated expiration 2023-07-08.
Source: https://patents.google.com/patent/US6939027/en
Purpose (plain language): The patent addresses a light source for projection systems such as projectors, where conventional sources (xenon or high-pressure mercury-vapor lamps) require color filters to limit transmission wavelengths. The invention instead builds a light source from light-emitting diodes (LEDs) of different colors—red, blue, and green—arranged at a predetermined ratio of quantities. That ratio is derived from measured light-emitting conditions (chromaticity, brightness) of each color so the projected light has the chromaticity of a desired color (e.g., white, W, in the chromaticity diagram). The total number of LEDs is set to satisfy that ratio.
Scope highlights from the excerpt: LEDs may be arranged on a spherical curved surface, an elliptical or parabolic surface of rotation, or in concentric multiple circles (optionally with same-color LEDs per circle, or mixed colors per circle). Emission may be controlled per color. The system may include a mixer for combining monochromatic lights and light-guiding means (a condenser lens on a 1:1 basis with each LED), plus a cone-shaped light source cover with the mixer at its vertex. It may also include a reflection mirror and condenser lenses, with 1:1 lens-array alternatives, supporting adjustable lightness/color by turning on selected diode quantities.
What the excerpt does not establish: It does not establish the full claim set, dependent-claim wording, prosecution history, the complete description or figures, any prior-art findings, validity, enforceability, current ownership beyond the recorded assignment, or litigation. Numerical examples (e.g., 36 red, 61 green, 35 blue) appear as illustrative text but the excerpt is incomplete. Classifications listed include H04N9/31, H04N9/315, H05B45/20, and Y10S362/80.
Generated 10/1/2026, 9:42:44 PM
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.